In a Dual Subscriber Identity Module (SIM) Dual Standby (DSDS) mobile communication device that support two subscriptions with single or dual radios installed, both subscriptions can be in Global System for Mobile communications (GSM) mode. For example, the first subscription may be in GSM mode with circuit-switched (CS) and packet-switched (PS) services, and the second subscription may be in GSM mode with only CS services. During cell reselection on the first subscription a five-second timer is started upon detecting a neighbor cell that meets all reselection criteria. The reselection criteria must be met for the duration of the five-second time period in order for the mobile communication device to select that neighbor cell to camp on.
The DSDS mobile communication device shares a single radio frequency (RF) chain between the two subscriptions. Since the RF chain is shared, the first subscription may or may not have access to the RF chain while the five-second timer is running or after expiration thereof. For example, the second subscription may be using the RF chain to engage in other high priority activity like short message service (SMS), a voice call, etc. As a result, a detected neighbor cell may or may not meet the cell reselection requirements for the duration of the five-second timer and the mobile communication device may end up camping on a cell which may not be the best cell.